Search

Abstract Our previous study introduced a barley protein microparticle for encapsulation of hydrophobic drug/nutraceutical, which could release nanoparticles upon gastric digestion and deliver encapsulated compound to a simulated intestinal environment intact. This work focused on evaluating the potential of liberated nanoparticles to improve the absorption of encapsulated compounds (e.g., β -carotene) using in vitro Caco-2 cell and ex vivo small intestine models. Nanoparticles obtained from gastric digestion of barley protein microparticles had a spherical shape and an average size of 351 nm. Nanoparticles showed low cytotoxicity in Caco-2 cells and their cellular uptake was dependent on time, concentration and temperature. In a Caco-2 cell monolayer model, significantly greater uptake and transport of β -carotene were observed when it was delivered by nanoparticles (15%), compared to free β -carotene suspension (2.6%). In an ex vivo rat jejunum model, nanoparticles showed the capacity to retain in small intestinal tissue. Approximately 2.24 and 6.04 μg nanoparticle were able to permeate through each cm2 intestinal tissue and translocate to the serosal side after 60 and 90 min, respectively. Results from this study demonstrated the absorption improving effect of the barley protein nanoparticles and suggested their potential as vehicles for hydrophobic compounds. Graphical abstract Barley protein microparticles could protect encapsulated compounds and prevent nanoparticles from aggregation during storage. Barley protein nanoparticles can be liberated from microparticles upon gastric digestion and demonstrate absorption improving effect in both Caco-2 cell and rat jejunum models. These vehicles show significant potential in the delivery of hydrophobic compounds. fx1 [ABSTRACT FROM AUTHOR]

Angiotensin converting enzyme (ACE) inhibitory peptides have been extensively studied as an alternative to synthetic drugs for the treatment of hypertension. Recent studies have shown that dry-cured ham is an important source of naturally generated bioactive peptides, especially showing ACE inhibitory activity. However, due to their excessive degradation by digestive and brush-border enzymes, it is not clear whether these peptides resist intestinal absorption and reach the blood stream where they may exert their antihypertensive effect. Therefore, dry-cured ham extracts and specific pure peptides naturally generated during the dry-curing process, showing ACE inhibitory activity, have been studied for their stability during transepithelial transport in a Caco-2 cell monolayer. The ACE inhibitory activity of transport samples was assayed, showing the highest values in apical samples at 15 min of incubation. In concentrated basal solutions, ACE inhibition values increased during transport for purified peptides, reaching values close to 70% for AAPLAP and KPVAAP at 60 min of cellular transport. Fragments generated by cellular activity were detected by using tandem mass spectrometry techniques, showing that AAATP, AAPLAP, and KPVAAP were hydrolysed during the transport, although KPVAAP was also absorbed intact. This study highlights the potential of intact dry-cured ham peptides as well as their fragments to be absorbed across the intestinal epithelium and reach the blood stream to exert an antihypertensive action. [ABSTRACT FROM AUTHOR]

The article focuses on a study related to the effect of lectins which was isolated from foodstuff on transport system Caco-2 cell monolayers of human intestinal. The study mentions that various properties of lecitins include sugar-binding specificity, protease digestion and stability against heat denaturation. The study further informs about various dietary lectins including as drug delivery agent, oral vaccine adjuvant and anti-cancer therapy.

Abstract: Hoodia gordonii was traditionally used by the Khoisan people as a thirst and appetite suppressant and is currently commercially available as a popular weight-loss supplement. The perceived active ingredient isolated from this plant is a steroidal glycoside named P57. This study aimed at investigating the in vitro transport of P57 across excised porcine intestinal and buccal mucosa in a Sweetana–Grass diffusion apparatus. For both the intestinal and buccal experiments, the transport of pure P57 was compared to that obtained from a crude plant extract. Bi-directional transport experiments were conducted across the intestinal tissue in two different media namely Krebs–Ringer bicarbonate buffer and simulated intestinal fluid. Apical-to-basolateral transport experiments were conducted across the buccal tissue in two different media namely Krebs–Ringer bicarbonate buffer and artificial saliva. Apparent permeability coefficient (P app ) and flux values were calculated and analysed by means of a one-way repeated analysis of variance (ANOVA) to determine if differences were significant (p ≤0.05). The transport of pure P57 across intestinal tissue was significantly higher in the secretory direction than in the absorptive direction indicating efflux by membrane transporters. Much higher intestinal transport was obtained for P57 in both directions when applied in the form of a crude extract, possibly due to inhibition of efflux as indicated by lower secretory transport compared to absorptive transport. For the buccal tissue, no transport was obtained for the pure P57, while relatively high transport was obtained when applied in the form of a crude extract. Furthermore, the intestinal transport of P57 was significantly decreased when the crude extract was prepared in simulated intestinal fluid compared to when it was prepared in buffer. On the other hand, buccal transport was higher in artificial saliva than in buffer. It is therefore evident that the transport of P57 across mucosal tissues is significantly affected on exposure to conditions simulating the in vivo situation. [Copyright &y& Elsevier]

Background & Aims: The transferrin receptor (CD71) is up-regulated in duodenal biopsy samples from patients with active celiac disease and promotes retrotransport of secretory immunolglobulin A (SIgA)-gliadin complexes. We studied intestinal epithelial cell lines that overexpress CD71 to determine how interactions between SIgA and CD71 promote transepithelial transport of gliadin peptides. Methods: We analyzed duodenal biopsy specimens from 8 adults and 1 child with active celiac disease. Caco-2 and HT29-19A epithelial cell lines were transfected with fluorescence-labeled small interfering RNAs against CD71. Interactions among IgA, CD71, and transglutaminase 2 (Tgase2) were analyzed by flow cytometry, immunoprecipitation, and confocal microscopy. Transcytosis of SIgA–CD71 complexes and intestinal permeability to the gliadin 3H-p31–49 peptide were analyzed in polarized monolayers of Caco-2 cells. Results: Using fluorescence resonance energy transfer and in situ proximity ligation assays, we observed physical interactions between SIgA and CD71 or CD71 and Tgase2 at the apical surface of enterocytes in biopsy samples and monolayers of Caco-2 cells. CD71 and Tgase2 were co-precipitated with SIgA, bound to the surface of Caco-2 cells. SIgA–CD71 complexes were internalized and localized in early endosomes and recycling compartments but not in lysosomes. In the presence of celiac IgA or SIgA against p31–49, transport of intact 3H-p31–49 increased significantly across Caco-2 monolayers; this transport was inhibited by soluble CD71 or Tgase2 inhibitors. Conclusions: Upon binding to apical CD71, SIgA (with or without gliadin peptides) enters a recycling pathway and avoids lysosomal degradation; this process allows apical–basal transcytosis of bound peptides. This mechanism is facilitated by Tgase2 and might be involved in the pathogenesis of celiac disease. [ABSTRACT FROM AUTHOR]